Historically, telecommunications have involved the transmission of voice and fax signals over a circuit switched network such as the Public Switched Telephone Network (PSTN) or the Public Switch Exchange (PBX). Likewise, data communications between computers have been historically transmitted over packet based networks using Internet Protocol (IP). Today, telecommunications and data transmissions have merged into an integrated communication network using technologies such as Voice over Internet Protocol (VoIP).
VoIP offers numerous advantages over a PSTN. For instance, VoIP increases user mobility as a user only needs a connection to the internet to enter into a communication session. Further, VoIP permits users in a shared line setting to barge into existing communication sessions and view details of communication sessions involving users of the shared line. VoIP also allows users to forward and/or transfer a call to a different line and clear the original communication line.
As new communication technologies become available, it is often difficult for users to assimilate the breadth of new features and functions. Despite the advantages offered by IP telephony, some features in circuit switched communication systems that users are accustomed to are not provided in VoIP implementations.